Headrest and vehicle seat provided with the same

ABSTRACT

Provided are a versatile and thin headrest, and seat for same, that can be operated smoothly by reducing an operation load at the time when the headrest is tilted from a head support state to a storage state, and is capable of preventing noise caused by the headrest. The headrest includes a pillar having a transverse shaft part and mounted to the upper part of the seat back, a headrest frame rotatably engaged with the transverse shaft part of the pillar, a headrest urging element that urges the headrest frame to one side, a locking element that hinders turning the headrest frame and pillar, a ratchet lever operating the locking element and sliding in the transverse direction, and a ratchet lever urging element, that urges the ratchet lever in the direction at a predetermined angle to the ratchet lever sliding in the transverse direction.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the U.S. national phase of the International PatentApplication No. PCT/JP2008/055889 filed Mar. 27, 2008, which claims thebenefit of Japanese Application No. 2007-095909, filed Mar. 31, 2007,the entire contents of which are incorporated herein by reference.

BACKGROUND

The present invention relates to a headrest and a vehicle seat providedwith the headrest. More particularly, it relates to a headrest capableof being made in a head support state in which the headrest is raisedwith respect to a seat back and in a storage state tilted from the headsupport state, and a vehicle seat provided with the headrest.

Generally, a headrest for protecting the passenger's head is mounted onthe upper part of a seat back of a vehicle seat. Conventionally, therehas been publicly known a configuration in which the lower part of apillar of the headrest is attached to a transverse rod, which extends inthe right and left direction in the seat back, so as to be rotatable inthe front and rear direction, and the pillar is attached so as to bemovable in the right and left direction, whereby the headrest is movedtransversely and then is tilted to the rear to be stored (see JapaneseUnexamined Utility Model Application Publication No. 7-11951,hereinafter, “JP '951”).

Also, there has been proposed a technique in which a headrest includes apillar that has a transverse shaft part and is mounted on the upper partof a seat back; a headrest main body the lower side of which isrotatably provided in the transverse shaft part of the pillar; and atilting mechanism incorporated in the headrest main body to tilt theheadrest main body to the rear, and the tilting mechanism includes aheadrest urging element or elements that urge the upper part of theheadrest main body to the rear side; a lock plate that is provided inthe transverse shaft part of the pillar and has a first locking part; alatch that is provided in the headrest main body and has a secondlocking part that lock to the first locking part of the lock plate; alatch urging element or elements that urge the latch so as to lock thesecond locking part to the first locking part of the lock plate; and anactuator that disengages the second locking part of the latch from thefirst locking part of the lock plate against the urging force of thelatch urging element or elements (see Japanese Unexamined PatentApplication Publication No. 2005-349915, hereinafter “JP '915”).

Furthermore, there has been proposed a technique in which in a tiltingheadrest in which a bracket can be moved to a folded position and to anerected position, a concave part is formed in a locking reciprocatingmember and a locking member, and the locking reciprocating member ismade slidable to a locked position and to an unlocked position by aspring (see U.S. International Patent Publication WO2005/120894A1,hereinafter “WO '894”).

The publicly known example of JP '951 has a problem in that the headrestrotates to the rear greatly together with the pillar and therefore thedisplacement thereof is large, and also the headrest occupies a largespace when being stored because the rotating support point of theheadrest exists in the upper part of the seat back under the headrest.

That is to say, when the headrest is tilted to the rear, the whole ofthe headrest projects to the rear side. This example also has a problemin that a pillar movement groove must be formed in the upper part of theseat back, so that not only is the construction complicated but also theheadrest cannot be used commonly for other seat backs.

The publicly known technique of JP '915 has high versatility because thetilting mechanism of the headrest can be accommodated entirely in theheadrest main body. However, this technique has a problem in that a sizeof some degree must be secured in the front and rear direction, and thethinning of headrest is limited because the first locking part of thelock plate and the second locking part provided on the latch to belocked to the first locking part are used, and the lock plate and thelatch are arranged in the tilt direction.

In the publicly known technique of WO '894, the concave part is formedin the locking reciprocating member and the locking member, and thelocking reciprocating member is made slidable to a locked position andto an unlocked position by the spring. Since the locked position and theunlocked position are changed over by the two members of the lockingreciprocating member and the locking member, a spring force for urging abracket in the fold direction is applied directly to the lockingreciprocating member and the locking member, so that in some cases, itis difficult for the reciprocating movement of the locking reciprocatingmember to be accomplished smoothly. Also, in the case where a pluralityof locking members are present, one locking reciprocating member is madeslidable to the locked position and the unlocked position with respectto all the locking members. Therefore, this technique has a disadvantagein that the locking reciprocating member becomes large, so that a higherload is applied to the locking reciprocating member.

Also, in any of the above-described publicly known techniques, in acondition where vibrations occur, for example, when the vehicle isrunning, consideration has not been given to abnormal sounds and noisecaused by the headrest.

SUMMARY

An object of the present invention is to provide a headrest that hashigh versatility, is thin in shape, and is capable of being operatedsmoothly by reducing an operation load at the time when the headrest istilted from a head support state to a storage state, and a vehicle seatprovided with the headrest.

Another object of the present invention is to provide a headrest capableof preventing abnormal sounds and noise caused by a headrest in acondition where vibrations occur, for example, when the vehicle isrunning, and a vehicle seat provided with the headrest.

To achieve the above objects, various embodiments of the presentinvention provide a headrest capable of being made in a head supportstate in which the headrest is raised with respect to a seat back and ina storage state tilted from the head support state, including asupporting member mounted on the upper part of the seat back; a headrestframe rotatably engaged with the supporting member; a frame urgingelement or elements that urge the headrest frame to one side; a lockingelement or elements that hinder the rotating of the headrest frame andthe supporting member; and an operation lever for operating the lockingelement or elements, wherein the operation lever having a concave partformed toward the supporting member side is formed so as to be movablein the direction different from the rotating direction of the headrestframe, and is urged in the predetermined direction by an operation leverurging element or elements.

At this time, it is preferable that the operation lever urging elementor elements urge the operation lever in the direction at a predeterminedangle to the movement direction of the operation lever.

To solve the above object, various embodiments of the present inventionprovide a headrest capable of being made in a head support state inwhich the headrest is raised with respect to a seat back and in astorage state tilted from the head support state, including a pillarhaving a transverse shaft part and mounted to the upper part of the seatback; a headrest frame rotatably engaged with the transverse shaft partof the pillar; a headrest urging element or elements that urge theheadrest frame to one side; a locking element or elements that hinderthe rotating of the headrest frame and the pillar; a ratchet lever thatoperates the locking element or elements and slides in the transversedirection; and a ratchet lever urging element or elements that urge theratchet lever, wherein the ratchet lever urging element or elementsurges the ratchet lever in the direction at a predetermined angle to theratchet lever sliding in the transverse direction.

By the above-described configuration, a force in the fixed direction isapplied to the operation lever (ratchet lever), and the movement in thedirection different from the movement direction of the operation lever(ratchet lever) is regulated by this force in the fixed direction, sothat looseness can be prevented, and the occurrence of abnormal sounds(noise) can be prevented.

In the above-described configuration, it is preferable that a covermaterial be disposed on the outer periphery side of the headrest frame;at the arrangement position of the ratchet lever of the cover material,a hole be formed so that the end part of the ratchet lever isextendable; a garnish be disposed in the hole; in the end part of theratchet lever extending from the garnish, an operation knob be disposed;and the operation knob coming closest to the garnish in the urgingdirection of the ratchet lever urging element or elements.

If the operation knob is configured so as to come closest to the garnishin the urging direction of the urging element or elements as describedabove, the distance between the operation knob and the garnish becomesshortest, or the operation knob comes into contact with the garnish, sothat looseness caused by swaying and the like during running can beprevented.

Also, in the above-described configuration, it is preferable that theheadrest frame be formed with at least a tongue piece, which is bent tothe inside toward the ratchet lever, on the opposite side to thearrangement position of the ratchet lever urging element or elements soas to hold the ratchet lever, and the tongue piece serve as a guide forthe ratchet lever.

By the above-described configuration, on the side of dispositionposition of the ratchet lever urging element or elements, the distancebetween the operation knob and the garnish is made shortest, or theoperation knob is brought into contact with the garnish, and on theother side, the position is fixed by a portion in which the ratchetlever comes into contact with the tongue piece and is guided. Therefore,looseness of the ratchet lever caused by swaying and the like duringrunning can be prevented, and the occurrence of abnormal sounds andnoise can be prevented.

To achieve the above object, various embodiments of the presentinvention provide a vehicle seat provided with the headrest having theabove-described configuration.

According to various embodiments of the present invention, there can beprovided a headrest that has high versatility, is thin in shape, and iscapable of being operated smoothly by reducing an operation load at thetime when the headrest is tilted from a head support state to a storagestate, and a vehicle seat provided with the headrest.

Also, in a condition where vibrations occur, for example, when thevehicle is running, abnormal sounds and noise caused by the headrest canbe prevented.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described below with reference to the variousembodiments illustrated in the drawings.

FIG. 1 is a perspective view of a seat provided with a seat back and aheadrest;

FIG. 2 is a sectional view taken along the line A-A of FIG. 1;

FIG. 3 is an exploded perspective view of a headrest frame and a lockingelements;

FIG. 4 is a perspective view of a headrest frame to which a pillar isassembled and a locking elements, viewed from the side on which theheadrest frame comes into contact with the passenger's head;

FIG. 5 is a front view of FIG. 4;

FIG. 6 is a rear view of FIG. 4;

FIG. 7 is a pictorial illustrative view of locking elements;

FIG. 8 is a sectional view taken along the line B-B of FIG. 5;

FIG. 9 is a perspective view of a pillar;

FIG. 10 is a perspective view of a ratchet lever;

FIG. 11 is a plan view of a ratchet;

FIG. 12 is a side view of a latch plate;

FIG. 13 is a schematic sectional view showing a transverse cross sectionof a headrest;

FIG. 14 is a partially expanded view of FIG. 13; and

FIG. 15 is a partially exploded perspective view of a cover.

DETAILED DESCRIPTION OF THE EMBODIMENTS

An embodiment of the present invention will now be described withreference to the accompanying drawings. The members, arrangements, andthe like explained below do not restrict the present invention, and canbe changed variously without departing from the spirit and scope of thepresent invention.

A vehicle seat S of this embodiment is an example of a rear seat of anautomobile seat. As shown in FIG. 1, the vehicle seat S includes a seatcushion 51 and a seat back S2, and in the upper part of the seat backS2, a headrest HR is provided. The seat cushion S1 and the seat back S2have a publicly known configuration in which a frame, a pad, and a seatcover material for covering the frame and pad are provided, andtherefore the details thereof are omitted. In this embodiment,explanation is given by taking the rear seat of the automobile seat asan example. However, the present invention can be applied to a frontseat or an intermediate seat of vehicle as far as the seat can bemounted with the headrest.

The headrest HR of this embodiment can be mounted on the seat back S2via a pillar 1 serving as a supporting member so that the height thereofcan be adjusted. To adjust the height of the headrest HR, a publiclyknown height adjusting mechanism can be used, and therefore the detailsof the mechanism are omitted.

As shown in FIG. 1, the headrest HR of this embodiment can be made in ahead support state in which the headrest HR is raised with respect tothe seat back S2 and in a storage state tilted from the head supportstate (in the example shown in FIG. 1, the left-hand side in the figureshows the storage state).

The headrest HR of this embodiment includes, as principal components,the pillar 1 (FIG. 3) serving as the supporting member, a headrest frame2 (FIG. 4) serving as a frame, headrest frame urging elements 3 (FIG. 6)serving as frame urging elements, and locking elements 4 (FIG. 7).

As shown in FIGS. 3 and 9, the pillar 1 serving as the supporting memberof this embodiment has two leg parts 11, 11 mounted on the upper part ofthe seat back S2, and a transverse shaft part 12 for connecting the twoleg parts 11, 11 to each other. To the transverse shaft part 12 of thepillar 1, latch plates 41 and 42 serving as locking members are fixedperpendicularly to the axis of the transverse shaft part 12 at apredetermined interval by welding or the like. A portion between thelatch plates 41 and 42 of the transverse shaft part 12 is rotatably heldby substantially semicircular lower assembling concave parts 21 a and 22a formed in the lower part of the headrest frame 2 (a main frame 21 anda sub frame 22) serving as the frame, described below.

The latch plates 41 and 42 of this embodiment constitute the lockingelements 4, described below.

The headrest frame 2 serving as the frame of this embodiment isrotatably engaged with the transverse shaft part 12 of the pillar 1 asdescribed above, and as shown in FIGS. 3 and 6, is configured by beingcombined by a plurality of hemming staking parts 21 r, 21 r and blankeddrawn parts 22 g each having a hole 22 h and hemming staking parts 21 band 22 b, described below, so that the sub frame 22 enters the mainframe 21.

In the headrest frame 2 comprising the main frame 21 and the sub frame22, a ratchet lever 44 serving as an operation lever and ratchets 46serving as fixing members are held. The main frame 21 and the sub frame22 are assembled integrally to each other by staking from both front andrear sides with rivets 101 and 102 being held between them. The centralparts 101 a and 102 a of the rivets 101 and 102 have a large diameter,and on both sides of the central parts 101 a and 102 a, staking parts101 b and 102 b are formed. The ratchet lever 44 and the ratchets 46 ofthis embodiment constitute the locking elements 4, described below.

As shown in FIGS. 3 and 5, the main frame 21 of this embodimentcomprises a rectangular plate body. In the lower part thereof, thesubstantially semicircular lower assembling concave part 21 a is formed,and the hemming staking part 21 b is formed so as to be continuous withthe lower assembling concave part 21 a. The lower assembling concavepart 21 a is formed with a cut-away part 21 m formed by cutting themiddle part, and a looseness preventing piece 21 k is formed so as to bedirected to the cut-away part 21 m. On both sides of the loosenesspreventing piece 21 k, slits 21 s are formed. This looseness preventingpiece 21 k has a spring effect due to the slits 21 s, and is in contactwith the transverse shaft part 12 of the pillar 1 so as to be pressedagainst the transverse shaft part 12. By this, the looseness betweenheadrest frame 2 and the pillar 1 can be prevented with more certainty.

On the upper side of the main frame 21, a jutting-out 21 g is formed.This jutting-out 21 g is in contact with a projecting portion of aresin-made front cover member 7 a, described below, and also secures thestrength.

Also, at the outer periphery of the main frame 21, a bent wall part 21 cis formed excluding predetermined ranges on both sides of the lowerassembling concave part 21 a.

On the inside of the main frame 21, boss parts 21 e are formed inportions, through which the rivets 101 serving as the rotation shaftsfor the ratchets 46 are inserted, so as to project toward the inside.Also, on the outer periphery side of the boss part 21 e, a substantiallyarc-shaped protruding part 21 f is formed so as to project toward therotating surface of the ratchet 46. This substantially arc-shapedprotruding part 21 f, together with a substantially arc-shapedprotruding part 22 f formed on the sub frame, described below, guidesthe ratchet 46 so that the ratchet 46 can be turned without play bybeing held between the protruding parts 21 f and 22 f.

On one side face of the bent wall part 21 c, a cut-away part 21 d isformed. The ratchet lever 44 is inserted through this cut-away part 21d. Also, on the extension of the cut-away part 21 d, three tongue pieces21 h, 21 i and 21 j that are bent toward the inside are formed so as toserve as guides at the time when the ratchet lever 44 is insertedthrough.

The two tongue pieces 21 h and 21 j of the three tongue pieces 21 h, 21i and 21 j are bent toward the inside from the upside to the downside,and are formed at an interval in the right and left direction. In asubstantially central portion of the tongue pieces 21 h and 21 jarranged in the right and left direction, one tongue piece 21 i that isbent toward the inside from the downside to the upside is formed. Theratchet lever 44 is inserted through by using the three tongue pieces 21h, 21 i and 21 j as the guides. The ratchet lever 44 of this embodimentconstitutes the locking elements 4, described below.

Furthermore, in the state in which the ratchet lever 44 is insertedthrough, at the position of the ratchet lever 44 of the main frame 21,embossed parts 21 p, 21 p directed to the ratchet lever 44 side areformed. The embossed parts 21 p, together with embossed parts 22 pformed on the sub frame 22, described below, guide the ratchet lever 44so that the ratchet lever 44 can be moved without play by being heldbetween the embossed parts 21 p and 22 p.

As shown in FIGS. 3, 6 and 7, the sub frame 22 of this embodimentcomprises a rectangular plate body, and is configured so that the upperpart of a predetermined position, that is, the arrangement position ofthe above-described ratchet lever 44 in this embodiment, is offset toone side (toward the direction distant from the cut-away part 21 d).

Also, as shown in FIGS. 6 and 7, a bent part 22 c is formed in the upperpart and at the right and left excluding the lower side. The inside ofthe bent part 22 c is formed as an expanding part 22 d expanding fromthe normal surface. This expanding part 22 d, together with an urgereceiving part 22 k, described below, makes the normal surface (on thefront side of paper of FIG. 6) low. By this, the configuration is madesuch that the rivets 101 and 102 and the hemming staking parts 21 r, 21r are at positions lower than the expanding part 22 d and the urgereceiving part 22 k, so that interference with other members can beprevented.

As shown in FIG. 7, at positions separating through a predetermineddistance from the centerline of the sub frame 22, the blanked drawnparts 22 g that project to the opposed main frame 21 side and have thehole 22 h for hemming staking are formed.

In the lower part of the sub frame 22, the substantially semicircularlower assembling concave part 22 a is formed, and the hemming stakingpart 22 b is formed so as to be continuous with the lower assemblingconcave part 22 a.

As described above, the main frame 21 and the sub frame 22 are staked inthe same direction from the main frame 21 side to the sub frame 22 sideby the hemming staking parts 21 r, 21 r and the blanked drawn parts 22 geach having the hole 22 h and the hemming staking parts 21 b and 22 b.Therefore, the working is easy as compared with the case of burring. Themain frame 21 side is configured so that the staking claw and the likeare not exposed, and the headrest frame side on the side of coming intocontact with the passenger's head is configured so that protrusions andthe like are absent as far as possible.

Also, on the opposite side to the hemming staking part 22 b, the urgereceiving part 22 k is formed by drawing so as to be continuous with thelower assembling concave part 22 a. As shown in FIG. 6, this urgereceiving part 22 k is configured so as to be in contact with the otherend 33 b of a spring 33, and is formed so as to be raised on the springarrangement side. Also, the urge receiving part 22 k is in contact withthe spring 33 constituting the headrest frame urging elements 3 and alsocomes into contact with a damper 32, described below, at the rotatingtime, thereby preventing looseness and noise.

The bent part 22 c (refer to FIG. 7) that is bent to the inside isformed in the upper part and at the right and left excluding the side onwhich the substantially semicircular lower assembling concave part 22 ais provided.

On the sub frame 22, boss parts 22 e projecting toward the inside areformed at positions matching the boss parts 21 e of the main frame 21,that is, in portions through which the rivets 101 serving as therotation shafts for the ratchets 46 are inserted. At positions of theratchet lever 44 of the sub frame 22, the embossed parts 22 p, 22 pdirected to the ratchet lever 44 side are formed.

Also, on the inside of the sub frame 22, the substantially arc-shapedprotruding parts 22 f projecting toward the rotating surface of theratchet 46 are formed so as to match the substantially arc-shapedprotruding parts 21 f formed on the main frame 21.

As shown in FIGS. 3 and 6, the headrest frame urging elements 3 servingas the frame urging elements are configured so as to urge the headrestframe 2 to one side (that is, the tilt side), and includes a shaft 31,the damper 32, the spring 33, shaft insertion holes 41 d and 42 d formedin the latch plates 41 and 42 constituting the locking elements 4, andthe above-described urge receiving part 22 k.

The shaft 31 is a round bar, and the damper 32 is formed by a hollowcylindrical body made of rubber. Also, the spring 33 is disposed so thatone end 33 a thereof is locked to the latch plate 41, and the other end33 b side is in contact with the damper 32. Also, the other end 33 b ismade a wide pressing part, and is brought into contact with theabove-described urge receiving part 22 k. By urging, at the normal time,the headrest frame 2 is subject to an urging force toward the tiltdirection.

In assembling, the shaft 31 is inserted between the two latch plates 41and 42. The shaft 31 is inserted through the shaft insertion hole 41 d(or 42 d) in one latch plate 41 (or 42), and then the damper 32 and thespring 33 are placed on the shaft 31. Next, the shaft 31 is insertedthrough the shaft insertion hole 42 d (or 41 d) in the other latch plate42 (or 41).

Symbol 4 shown in FIG. 7 denotes the locking elements, which areprovided between the pillar 1 and the headrest frame 2.

The locking elements 4 of this embodiment include, as principalcomponents, the latch plates 41 and 42 serving as the locking members,the ratchet lever 44 serving as the operation lever, the ratchets 46serving as the fixing members, and a spring 45 serving as a ratchetlever urging elements (operation lever urging elements).

As described above, the latch plates 41 and 42 of this embodiment arefixed to the transverse shaft part 12 of the pillar 1 perpendicularly tothe axis of the transverse shaft part 12 at a predetermined interval bywelding or the like.

As shown in FIG. 9, in the upper parts of the latch plates 41 and 42,engagement groove parts 41 a and 42 a are formed along the transverseshaft part 12.

On the latch plates 41 and 42, arcuate outer peripheral parts 41 b and42 b and stopper parts 41 c and 42 c configured by walls of portions ofthe engagement groove parts 41 a and 42 a are formed.

In this embodiment, the latch plates 41 and 42 are formed so that theengagement groove parts 41 a and 42 a have a different shape. Theengagement groove part 42 a of the latch plate 42 provided on theright-hand side in FIG. 9 is formed so that the upper end side thereofis narrower, and the engagement groove part 41 a of the latch plate 41provided on the left-hand side in FIG. 9 is formed into a shape suchthat the groove width is unchanged in the up and down direction. On theend part side (the lower side in FIG. 9) on the side on which theheadrest frame 2 of the latch plates 41 and 42 tilts, stopper parts 41 eand 42 e are formed.

FIG. 12 is a side view of the latch plate 42. The upper side of theengagement groove part 42 a of the latch plate 42 tilts to the insidewith a portion that is slightly wider than the thickness of the ratchet46 being left (angle α in FIG. 12). Thus, in this embodiment, theengagement groove part 42 a of at least one latch plate (in thisembodiment, the latch plate 42) is formed so that the upper end side isnarrower. Therefore, the contact points between the latch plate 42 andthe ratchet 46 in an raised state are an upper end part 42 f of theengagement groove part 42 a of the latch plate 42 and a lock engagementpoint 46 c of the ratchet 46 shown in FIG. 11. The lock engagement point46 c, which is the contact point, is at a side position at the time whenthe ratchet 46 comes into contact with a groove bottom 42 g of theengagement groove part 42 a of the latch plate 42.

Symbol 46 d shown in FIG. 11 denotes a locus along which the ratchet 46is moved from a disengagement position deviating from the engagementgroove part 42 a to a position at which the ratchet 46 comes intocontact with the groove bottom 42 g of the engagement groove part 42 aof the latch plate 42.

That is to say, as shown in FIG. 7, the configuration is made such thatthe portion that comes into contact with the ratchet 46 on the upper endside formed so as to be narrow of the latch plate 42 has a largerdistance Z from the transverse shaft part 12 of the pillar 1 than otherparts located in the engagement groove part 42 a of the ratchet 46.Therefore, the contact point separates from the axis (the rotationcenter of the headrest frame 2) of the transverse shaft part 12 of thepillar 1, and when the ratchet 46 moves from the engagement position tothe disengagement position (when the locking is released), the releaseload due to the urging force of the headrest frame urging element 3 (thespring 33) from the rear can be reduced, which enables the adjustment ofrelease load. In the case of this embodiment, the engagement groove part42 a of the latch plate 42 located on the side engaging with anoperation knob of the ratchet lever 44 is formed so as to have a narrowwidth, so that the transmission of a force from the ratchet lever 44 canbe accomplished with certainty.

Also, the latch plates 41 and 42 are provided with the shaft insertionholes 41 d and 42 d for inserting the shaft 31, respectively.

As shown in FIG. 10, the ratchet lever 44 of this embodiment is formedby a slender plate body. A main plate body 44 a slides in the transversedirection, and the main plate body 44 a is formed with engagementconcave parts 44 b, 44 b directed to the pillar 1 side. On the oppositeside to the engagement concave parts 44 b, 44 b, a movement locking part44 c is formed substantially at right angles to the main plate body 44a, and the movement locking part 44 c is formed with a locking part 44 dof the ratchet lever urging element 45.

Each of the engagement concave parts 44 b, 44 b is formed betweenjutting-out parts 44 f, 44 f projecting from the main plate body 44 a tothe pillar 1 side, and is formed so as to hold one circular end side ofthe ratchet 46 and to allow the ratchet 46 to rotate.

To the ratchet lever 44, one end of the ratchet lever urging element(the spring 45) is connected so that the ratchets 46 are urged in thedirection of the engagement groove parts 41 a and 42 a of the latchplates 41 and 42. Symbol 44 e denotes the end part side engaged with theoperation knob.

At this time, in the movement locking part 44 c of the ratchet lever 44,a locking part 44 d on one end side of the spring 45 is formed, and inthe bent wall part 21 c of the main frame 21 located on the lower side(FIG. 6) of the locking part 44 d of the spring 45, a locking part 21 uon the other side of the spring 45 is formed (refer to FIG. 4). Asindicated by an arrow mark in FIG. 6, due to the difference in lockingposition, the spring 45 urges the movement locking part 44 c of theratchet lever 44 slantwise downward.

The main frame 21 is formed with the tongue pieces 21 h and 21 i. Whenthe ratchet lever 44 is urged as indicated by the arrow mark in FIG. 6,the other end side of the ratchet lever 44 is urged to the tongue piece21 h side with the tongue piece 21 i being a support point. Therefore,the operation knob 47 side of the ratchet lever 44 comes closest to orinto contact with the garnish 7 d, and the other side thereof comes intocontact with the tongue piece 21 h, whereby the movement in the up anddown direction is regulated. By doing this, in a condition wherevibrations occur, for example, when the vehicle is running, abnormalsounds and noise caused by the movement of the ratchet lever 44 can beprevented.

FIG. 15 shows an assembled state of a cover material 7. After the pillar1 serving as the supporting member, the headrest frame 2 serving as theframe, the headrest frame urging elements 3 serving as the frame urgingelements, the locking elements 4, and the like have been assembled,these elements are covered with the cover material 7. The cover material7 includes the resin-made front cover member 7 a and rear cover member 7b, a seat cover fastening cover member 7 c, and a garnish 7 d forpreventing the operation knob and the like of the control section fromcoming off.

As shown in FIG. 2, a pad material 8 is disposed at the outer peripheryof the cover material 7, and a seat cover material 9 covers the padmaterial 8.

FIG. 13 is a schematic sectional view showing the transverse crosssection of the headrest, and FIG. 14 is a partially expanded view ofFIG. 13. Referring to these figures, a state in which the operation knob47 side comes closest to or into contact with the garnish 7 d isexplained.

As shown in FIG. 13, the headrest frame is covered with the covermaterial 7 comprising the resin-made front cover member 7 a and rearcover member 7 b. At this time, the cover material 7 is formed with ahollow cylindrical flange part 7 f so that the cylindrical flange part 7f surrounds the end part of the ratchet lever 44. In this cylindricalflange part 7 f, the garnish 7 d is disposed. The terminal treatment isaccomplished by holding the end part of the seat cover material 9between the cylindrical flange part 7 f and the garnish 7 d. The endpart 44 e of the ratchet lever 44 extends from a space formed by thecylindrical flange part 7 f and the garnish 7 d, and the operation knob47 is attached to the end part 44 e. Since the movement locking part 44c of the ratchet lever 44 is urged slantwise downward by theabove-described spring 45, the operation knob 47 comes closet to or intocontact with the garnish 7 d, so that regulation is accomplished.

As shown in FIGS. 3, 7 and 11, the ratchet 46 of this embodimentincludes a rotation hole 46 a serving as a rotation axis, an engagementpart 46 b, and the lock engagement point 46 c, and is pivotallysupported on the headrest frame 2 with the rivet 101 arranged betweenthe main frame 21 and the sub frame 22 being used as a rotation shaft.

On the inside (the opposed side) of the main frame 21 and the sub frame22, the substantially arc-shaped protruding parts 21 f and thesubstantially arc-shaped protruding parts 22 f are formed so as toproject toward the rotating surface of the ratchet 46 to guide therotating of the ratchets 46.

The engagement part 46 b on one end side of the ratchet 46 engages withthe engagement concave part 44 b, 44 b of the ratchet lever 44, and thelock engagement point 46 c on the other end side engages with theengagement groove part 41 a, 42 a of the latch plate 41, 42, whereby theraised state of the headrest HR is kept.

The engagement part 46 b on one end side of the ratchet 46 engages withthe engagement concave part 44 b, 44 b of the ratchet lever 44, and thesurface tangent to the engagement concave part 44 b, 44 b is formed intoa circular shape, preferably into a complete round shape. Thereby, theratchet 46 can be rotated stably following the movement of the ratchetlever 44. The ratchet 46 has a thickness larger than that of the ratchetlever 44. Therefore, the ratchet 46 can be prevented from coming off theratchet lever 44.

Also, as shown in FIG. 11, the distance X1 between the center of therotation hole 46 a of the ratchet 46 and the center of the engagementpart 46 b on one end side of the ratchet 46 engaging with the engagementconcave part 44 b of the ratchet lever 44 is set so as to be longer thanthe distance Y1 between the center of the rotation hole 46 a of theratchet 46 and the position of the lock engagement point 46 c (in FIG.11, the locus 46 d) on the other end side of the ratchet 46 crossinglyengaging with the engagement groove part 42 a of the latch plate 42.Thereby, the release load at the time when the engagement (locking) ofthe ratchet 46 with the latch plate 41, 42 is released can be reduced.

That is to say, in this embodiment, in the raised state, the ratchet 46pivotally supported on the headrest frame 2 is urged toward the tiltdirection by the spring 33, so that friction occurs in a portion inwhich the ratchet 46 is in contact with the engagement groove part 42 aof the latch plate 42. Therefore, when the ratchet 46 is rotated fromthe engagement position at which the ratchet 46 is positioned in theengagement groove part 42 a of the latch plate 42 to the disengagementposition at which the ratchet 46 deviates from the engagement groovepart 42 a, frictional resistance arises, so that a state in which theratchet 46 is difficult to rotate is formed.

However, the ratchet 46 of this embodiment is formed so that thedistance X1 between the center (support point) of the rotation hole 46 aand the center (power point) of the engagement part 46 b to which a loadis applied by the ratchet lever 44 is longer than the distance Y1between the center (support point) of the rotation hole 46 a and theposition (point of application) of the lock engagement point 46 ccrossingly engaging with the engagement groove part 42 a of the latchplate 42. Therefore, the ratchet 46 can be moved from the engagementposition to the disengagement position with a small force. That is tosay, a so-called link ratio can be set, and thereby the release load canbe adjusted.

Also, since the ratchet lever 44 is configured so as to hold onecircular end side of the ratchet 46 and to allow the ratchet 46 torotate, the engagement part 46 b on one end side of the ratchet 46 isheld in the engagement concave part 44 b of the ratchet lever 44, andalways engages with the ratchet lever 44, so that the turning of onlyone ratchet 46 can be prevented. That is to say, the ratchets 46smoothly turn always following the movement of the ratchet lever 44,malfunction is prevented, and a changeover due to the locking elements 4can be accomplished with certainty.

The ratchet 46 of this embodiment can rotate in a rotation angle rangeof 20 to 40 degrees around the rotation hole (rotation axis) 46 a.

If the ratchet 46 is configured so as to rotate in a rotation anglerange of 20 to 40 degrees around the rotation hole (rotation axis) 46 a,disengagement of the ratchet 46 from the latch plate 41, 42 due to therotation from the engagement position to the disengagement position andthe transverse displacement of the ratchet lever 44 for the rotation ofthe ratchet 46 can be adjusted so as to be optimum. Thus, thedisplacement relating to the operation can be adjusted by the lockingelements 4.

The seat cover material 9 of this embodiment is formed into a bag shapeone end side of which is open. The front cover member 7 a and the rearcover member 7 b in which the headrest frame 2 and other various membersare fitted are inserted through the opening part, and the seat coverterminal part on the opening side of the seat cover material 9 iscovered by the seat cover fastening cover member 7 c. An assembly of theseat cover material 9 and the cover material 7 is arranged in the cavityof a mold, and foaming is performed by injecting a foaming resin into aspace between the seat cover material 9 and the cover material 7,whereby the pad material 8 is molded integrally with the seat covermaterial 9 and the cover material 7.

Next, the operation of the headrest HR configured as described above isexplained.

Since the headrest frame 2 of the headrest HR is rotatably mounted tothe transverse shaft part 12 of the pillar 1, and is fixed by thelocking elements 4, the headrest HR at the normal time can protect thehead of a seated person when a shock is applied in a raised state.

That is to say, the pillar 1 mounted on the upper part of the seat backS2 has the transverse shaft part 12, and the transverse shaft part 12 ofthe pillar 1 and the headrest frame 2 are rotatably engaged with eachother. At the normal time, the headrest frame 2 is urged so as to betilted by the headrest frame urging elements 3. In the case of theraised state, the tilt is made in a locked state by the locking elements4 provided between the headrest frame 2 and the pillar 1. This raisedstate is shown in FIGS. 4 to 7. Therefore, the headrest HR is in theraised state as shown in FIG. 2.

In the locking elements 4, when the engagement part 46 b on one end sideof the ratchet 46 is pushed by the sliding motion of the ratchet lever44, the ratchet 46 rotates around the rotation axis, and the lockengagement point 46 c on the other end side of the ratchet 46 moves inthe direction crossing the engagement groove part 41 a, 42 a of thelatch plate 41, 42.

In the case of the raised state, the ratchet 46 is located in theengagement groove part 41 a, 42 a and is in contact with the latch plate41, 42. Therefore, the pillar 1 and the headrest frame 2 are in a lockedstate, and the raised state of the headrest HR is kept.

By operating the ratchet lever 44 against the ratchet lever urgingelement 45, the engagement part 46 b on one end side of the ratchet 46is pushed, and the ratchet 46 is rotated around the rotation axis.Therefore, the ratchet 46 retracts from the engagement groove part 41 a,42 a, and the ratchet 46 comes off the engagement groove part 41 a, 42 aof the latch plate 41, 42. At this time, at the normal time, the spring33, which is the headrest frame urging element 3, urges the headrestframe 2 toward the tilt direction, so that the headrest HR tilts aroundthe transverse shaft part 12, becoming in a storage state.

As described above, when the headrest HR is made in the head supportstate in which the headrest HR is raised with respect to the seat backS2 and in the storage state tilted from the head support state, in thepresent invention, the ratchet lever 44, the latch plates 41 and 42, andthe ratchets 46 are used as the locking elements 4, and the changeoverbetween the engagement position and the disengagement position isaccomplished via the ratchet 46 one end side of which engages with theengagement concave part 44 b of the ratchet lever 44 and the other endside of which can crossingly engage with the engagement groove part 41a, 42 a of the latch plate 41, 42. Therefore, the locking elements 4themselves can be configured so as to be compact without requiring agreat width. Moreover, since at least one of the engagement groove parts41 a and 42 a of the latch plates 41 and 42 serving as the lockingmembers is formed so that the upper end side thereof is narrower, thecontact point between the latch plate 42 and the ratchet 46 separatesfrom the transverse shaft part 12 of the pillar 1. Therefore, therelease load due to the urging force of the headrest frame urgingelement 3 (the spring 33) from the rear at the time when the locking isreleased can be reduced.

Also, at the normal time, by the ratchet lever urging element 45, theratchet lever 44 is urged in the direction in which the ratchet 46 isengaged with the engagement groove part 41 a, 42 a of the latch plate41, 42. By the operation of the ratchet lever 44 against the ratchetlever urging element 45, the ratchet 46 is disconnected from theengagement groove part 41 a, 42 a, and by the headrest frame urgingelement or elements 3, the headrest frame 2 is tilted to the storagestate, so that the headrest HR tilts. Therefore, the locking of thelocking elements 4 can be released by one operation (one action).

Furthermore, by making one end side of the ratchet 46, which is incontact with the engagement concave part 44 b of the ratchet lever 44,circular, the ratchet 46 is turned smoothly in the engagement concavepart 44 b of the ratchet lever 44 with the movement of the ratchet lever44. Therefore, the ratchet 46 can be engaged with and disengaged fromthe engagement groove part 41 a, 42 a of the latch plate 41, 42, so thatan exact locking releasing operation can be performed.

In the case where the headrest HR in the storage state is made in theraised state, since at the normal time, the ratchet lever 44 is urged bythe ratchet lever urging element (spring) 45, and the ratchet 46 isurged in the direction in which the ratchet 46 engages with theengagement groove part 41 a, 42 a of the latch plate 41, 42, when theheadrest HR is raised by hand, the ratchet 46 rotates and the lockengagement point 46 c engages with the engagement groove part 41 a, 42 aof the latch plate 41, 42, whereby a locked state is established.

In the above-described embodiment, two latch plates 41 and 42 serving asthe locking members of the locking elements 4, and two ratchets 46serving as the fixing member are provided. However, the number of theseelements may be one or three or more. It is a matter of course thataccording to the number, one or a plurality of engagement concave parts44 b of the ratchet lever 44 serving as the operation lever can beformed.

DESCRIPTION OF SYMBOLS

-   1 pillar-   2 headrest frame-   3 headrest frame urging element or elements-   4 locking element or elements-   7 cover material-   7 a front cover member-   7 b rear cover member-   7 c seat cover fastening cover member-   7 d garnish-   7 f cylindrical flange part-   8 pad material-   9 seat cover material-   11 leg part-   12 transverse shaft part-   21 main frame-   21 a lower assembling concave part-   21 b hemming staking part-   21 c bent wall part-   21 d cut-away part-   21 e boss part-   21 f protruding part-   21 g jutting-out part-   21 h, 21 i, tongue piece 21 j-   21 k looseness preventing piece-   21 m cut-away part-   21 p embossed part-   21 r hemming staking part-   21 s slit-   21 u locking part-   22 sub frame-   22 a lower assembling concave part-   22 b hemming staking part-   22 c bent part-   22 d expanding part-   22 e boss part-   22 f protruding part-   22 g blanked drawn part-   22 h hole-   22 k urge receiving part-   22 p embossed part-   31 shaft-   32 damper-   33 spring-   33 a one end-   33 b the other end-   41, 42 latch plate-   41 a, 42 a engagement groove part-   41 b, 42 b outer peripheral part-   41 c, 42 c stopper part-   41 d, 42 d shaft insertion hole-   41 e, 42 e stopper part-   42 f upper end part-   42 g groove bottom-   44 ratchet lever-   44 a main plate body-   44 b, 44 b engagement concave part-   44 c movement locking part-   44 d locking part-   44 e end part-   44 f, 44 f jutting-out part-   45 ratchet lever urging element or elements (spring)-   46 ratchet-   46 a rotation hole-   46 b engagement part-   46 c lock engagement point-   46 d locus-   47 operation knob-   101, 102 rivet-   101 a, central part 102 a-   101 b, staking part 102 b-   S vehicle seat-   S1 seat cushion-   S2 seat back-   HR headrest

1-6. (canceled)
 7. A headrest having a head support state in which theheadrest is raised with respect to a seat back and a storage statetilted from the head support state, comprising: a supporting membermounted on the upper part of the seat back; a headrest frame rotatablyengaged with the supporting member; a frame urging element or elementsthat urge the headrest frame to one side; a locking element or elementsthat hinder the rotating of the headrest frame and the supportingmember; and an operation lever that operates the locking element orelements, wherein the operation lever having a concave part formedtoward the supporting member side is formed so as to be movable in thedirection different from the rotating direction of the headrest frame,and is urged in the predetermined direction by an operation lever urgingelement or elements.
 8. The headrest according to claim 7, wherein theoperation lever urging element or elements urges the operation lever inthe direction at a predetermined angle to the movement direction of theoperation lever.
 9. A headrest capable of being made in a head supportstate in which the headrest is raised with respect to a seat back and ina storage state tilted from the head support state, comprising: a pillarhaving a transverse shaft part and mounted to the upper part of the seatback; a headrest frame rotatably engaged with the transverse shaft partof the pillar; a headrest urging element or elements that urge theheadrest frame to one side; a locking element or elements that hinderthe rotating of the headrest frame and the pillar; a ratchet lever thatoperates the locking element or elements and slides in the transversedirection; and a ratchet lever urging element or elements that urge theratchet lever, wherein the ratchet lever urging element or elementsurges the ratchet lever in the direction at a predetermined angle to theratchet lever sliding in the transverse direction.
 10. The headrestaccording to claim 9, further comprising: a cover material that isdisposed on an outer periphery side of the headrest frame; a hole thatis formed at an arrangement position of the ratchet lever of the covermaterial, so that an end part of the ratchet lever is extendable; agarnish that is disposed in the hole; an operation knob that is disposedin the end part of the ratchet lever extending from the garnish, theoperation knob coming closest to the garnish in the urging direction ofthe ratchet lever urging element or elements.
 11. The headrest accordingto claim 9, wherein the headrest frame is formed with at least a tonguepiece, which is bent to the inside toward the ratchet lever, on anopposite side to the arrangement position of the ratchet lever urgingelement or elements so as to hold the ratchet lever, and the tonguepiece serves as a guide for the ratchet lever.
 12. A headrest accordingto claim 1, wherein: the headrest frame is formed by combining a mainframe and a sub frame, and at least a part of the operation lever islocated between the main frame and the sub frame, and the main frame andthe sub frame are connected to each other by a staking part.
 13. Theheadrest according to claim 12, wherein the staking part is formed bystaking a lower assembling concave part of the sub frame to a lowerassembling concave part of the main frame.
 14. The headrest according toclaim 12, wherein the staking part is connected by a plurality ofhemming staking parts including a hemming staking part from the lowerassembling concave part of the main frame to the lower assemblingconcave part of the sub frame.
 15. The headrest according to claim 12,wherein the main frame is formed with a notch part formed by cutting amiddle part of the lower assembling concave part, a looseness preventingpiece formed with slits on both sides thereof is formed so as to bedirected to the notch part, and the looseness preventing piece is incontact with the transverse shaft part of the pillar.
 16. The headrestaccording to claim 12, wherein at least one of the main frame and thesub frame is formed with an embossed part projecting to the operationlever side to guide the operation lever.
 17. The headrest according toclaim 12, wherein at an outer periphery on a side on which the mainframe and the sub frame are opposed to each other, a bent wall part isformed in the upper part and at the right and left excluding the lowerside.
 18. The headrest according to claim 17, wherein the bent wall partof the main frame is formed with a notch part, through which theoperation lever is inserted, in one side surface thereof.
 19. Theheadrest according to claim 12, wherein the main frame is formed with aplurality of tongue pieces bent to the inside toward the operationlever, and a distance of the width in the direction in which theoperation lever is short is secured by the tongue pieces formed byholding the operation lever therebetween so that the tongue pieces serveas guides at the time when the operation lever is inserted.
 20. Avehicle seat provided with a headrest having a head supporting state inwhich the headrest is erected with respect to a seat back and in astorage state tilted from the head supporting state, wherein: theheadrest comprises: a supporting member mounted in the upper part of theseat back; a headrest frame rotatably engaged with the supportingmember; a frame urging element or elements that urge the headrest frameto one side; a locking element or elements that hinder the turning ofthe headrest frame and the supporting member; and an operation leverthat operates the locking element or elements, and the operation leverhaving a concave part formed toward the supporting member side is formedso as to be movable in the direction different from the turningdirection of the headrest frame, and is urged in the predetermineddirection by an operation lever urging element or elements.